Elizabeth Creed is Senior Systems En­gineer in Underwater Glider Systems, Kongsberg Underwater Technology, Inc. She explains that the term underwater vehicle in this context is an instrument placed in­side a pressure proof hull and which can perform certain tasks under water. Moreover, Seaglider is an autonomous underwater vehicle.

“That means that it is unmanned,” explains Elizabeth Creed. “It has no form of mooring ei­ther, but operates completely independently and communicates with a command centre via satel­lite only when on the water’s surface.”

“And that is when it receives a message telling it what to do?”

“That’s correct. When it’s on the water’s surface, it downloads all control files waiting for it from the command centre computer. It also transfers all the data collected during its last dive. It finds the new GPS coordinates and calculates the most appropriate method to carry out the next dive. As soon as these calculations have been completed, Seaglider dives back under the water’s surface.”

“It sounds like an extremely diligent and skilled worker. What is its highest utilitarian value and what were your practical goals for the product when it was developed?”

“We had a number of goals. Firstly, we wanted it to be small and practical, so that it could be car­ried by two persons alone. Secondly, we wanted to develop something that could be used on a number of different vessels, from small RIBs to large ships. Seaglider can operate for up to ten months at a time and can collect high resolution images, sound and other important oceano­graphic information. It requires absolutely no assistance from above the water’s surface when in operation. It navigates using GPS on the sur­face and what we call dead-reckoning when sub­merged,” explains Elizabeth Creed.

She emphasises that although Seaglider has two-way communications with the command centre, this does not imply that an operator is physically required to sit at the command centre computer. Any monitoring or adaptation to Seaglider’s opera­tions can be performed via Internet – anywhere in the world.

“Seaglider has also been designed to withstand a wide range of temperatures and weather condi­tions. It can just as easily operate under the equator as it can in Arctic waters. It can operate under ice and in storms.”

“How does Seaglider differ from other autono­mous underwater vehicles?”

“First and foremost, it is relatively inexpensive. Secondly, it can operate for ten months at a time whereas vehicles with propellers often only man­age a few days. Seaglider is also a very quiet vehi­cle, which can be beneficial if you want to perform so-called unobtrusive surveys. It can operate in areas with very varying visibility under water and it is so small that it can be used on relatively small boats.”

“Finally, can you describe the technology used in Seaglider?”

“Seaglider moves between the seabed and the water’s surface by moving oil between a reservoir within the pressure proof hull and a bladder fitted outside the hull. When oil is pumped into the blad­der, the bladder increases in volume. This gives more buoyancy to the glider and it can therefore start to ascend. If it wants to go deeper, it reverses the operation. The wings allow Seaglider to move forwards.”

“Where is Seaglider most valuable?”

“There are many areas which it is valuable but per­haps the most important are marine research, oil and gas, so-called tactical oceanography and within the fishing industry,” concludes Elizabeth Creed.